Circuit-coupling for electrically-heated utensils.



F. E. CARLSON.

CIRCUIT COUPLING FOR ELECTRICALLY HEATED UTENSILS..

APPLICATION FILED NOV. 28,1914.

Patented Apr. 10,1917.

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WITNESSES:

B y j Z/IWJ A TTOR NE Y ED %TATES PATENT @FFTQE.

FREDERICK E. CARI-SON, OF NEW BRITAIN, CONNECTICUT, ASSIGNUE T LANDEEW,FRARY & CLARK, OE NEW BRITAIN, CUNNECTICUT, A COfiPQRATEON 0F GUNNECTIC'UT.

messes.

Specification of Letters Patent.

Patented Apr. 119, 3191?.

Application filed November 28, 191%. Serial 380. 874,495.

utensils of various sorts, such for instance.

as curling irons, combs, etc., into an electrical circuit, and has forits object the provision of a swivel connection which will permit ofthe. utensil being turned w1thout twisting the cord, and WhlCh is simpleand inexpensive to manufacture and assemble, efiective in providing agood electrical contact and easy to manipulate. a

' The invention is shown as applied to the handle of a utensil such as acurlingfiron,

and-

Figure 1 is a central vertical section of the plug attached to thehandle. p Fig. 2 is a central vertical section of the receptacle. i Fig.3 is a bottom view of the plug member.

Fi 4 is a side view of the plug looki rom the right of Fig. 1, the capbeing "shown in section.

Referring to the drawings, a denotes the .handle, I), b, .the terminals0f the heater circuit of the utensil, these termlnals being I separatedby a wall 0, of insulation. d is acap of insulating material secured tothe endf of the handle, as bythe screws e, and

' on which the contact'plug f is mounted. e0" This'plug comprises ametallicsleeve 1, reduced in diameter at its end as; indicated at 2,-tofit in an aperture 3 in the top of the "leap, (Z, and providing ashoulder whlch rests pen the cap at the edge of the aperture. Above thissleeve is located an insulating washer 4, and above this washer, asecond metallic sleeve 5. A tubular bushing 6 of insulating materialpasses through these sleeves and washer, completely insulating the lowersleeve 1 from t e uppersleeve 5. 1 Through this bushing asses a screw 7,the head 8 of which is in e ectrlcal contact with the upper sleeve 5.Within the cap d and mounted on the end of the insulating bushing 6 sothat it is in electrical contact with the sleeve 1 is a spring contact 9adapted to bear upon and make-electrical contact with one terminal I) ofthe heater circuit.

* A second spring contact 10, separated from the contact 9 by aninsulating washer 11, is in electrical connection through the screw '7with the sleeve 5, and is adapted to make electrical contact with theother heater circuit terminal I). The spring contacts 9, 10, are passedthrough notches 13, 1 1, in the edges of the washer 11, to prevent themfrom turning. relatively thereto, and the screws e extend through othernotches 17, 18, in the edge of the washer to prevent the washer turninif the nut 12 should be come loosened. T is insures that under allconditions the spring contacts will be held in proper position to engagethe ends of the terminal screws, 1), 6'. These sleeves, insulatingWashers and spring contacts, are held in assembled position on the screw7 by the nut 12, and it will be seen that the circuit from the heaterterminal I) is through the spring contact 9 to the sleeve 1, and

from the heater terminal I) through the spring contact 10, screw 7,screw-head 8, to the metallic sleeve 5. The sleeves l and 5 arecircumferentially grooved as at 15, 16.

The complete receptacle shown in Fig. 2 and indicated generally by 20,comprises an inner shell 21 and an inclosing casing 22, these two partsbeing secured together as bye pin 23. The shell 21 is chambered as at 24to receive the plug f which fits closely therein. The wall of thechamber in oppois removed. The springs 29, 30, are fastened to the shell21 as by the screws 35, 36, under the heads of which the ends of thecircuit wires 37, 38 are fastened, the shell having an upstanding wall39 which is of course of insulating material and isolates the twocircuit terminalsto avoid any possibility of short-circuiting at thispoint. The end of the shell is apertured as at 40 to receive the circuitwires and the encircling spring guard 41. N

It is apparent that. the form of the electrical connection between theplug and the receptacle is such that there is a good mechanicalconnection for both sides of the circuit by the fitting of the exposedparts of the balls into the grooves, and that this connection is acomplete and easily operating swivel which will permit the utensil to beturned without limit and avoid twisting of the cord. The plug isgenerally of uniform diameter and it is single so that there can be nodoubt as to the proper method of its connection withthe receptacle. Thecircuit terminals are inclosed within the shell and out of alinementwith one another, making it quite diflicult, if not impossible, toaccidentally short-circuit them, and the manner of connecting up the pluwith the heater terminals avoids the use 0 wire connections.

' I claim as my invention:

1. The combination with exposed circuit terminals, of a cap inclosingsaid terminals and secured in position, a plug su ported by said cap,contacts carried by said plu and adapted for electrical engagement witsaid exposed terminals, sleeves of conducting material forming a part ofsaid plug insulated from one another, electrical connection between oneof said sleeves and one of said contacts, and between the other of saidsleeves and the other contact, circumferential grooves formed exteriorlyof each sleeve, a receptacle chambered to receive said plug,

contact members located in the walls of sa1d receptacle in alinementwith and adapted to fit in said grooves, yieldin means for bold: ingsaid contact members in place, and electrical conductors connecting saidcontacts why and mechanically to permit relative 1'0 with a supplycircuit.

2. The combination wlth' exposed circuit terminals, of a cap inclosingsaid terminals,

. a plug supported by said cap, said plug comprising a pair of springcontact members 10- cated within said cap, electrically insulated fromone another at one end and havin their opposite ends adapted forelectrica contact with said terminals, sleeves of electrical conductingmaterial located outside of said cap insulated from one another,electrical connection between one of said sleeves and one of saidcontact members, and between the other sleeve and the other contactmember, a circumferential groove in the exterior surface of each of saidsleeves, and

means for securing said cap and its supported parts in place.

3. The combination with exposed circuit terminals, of a plug connectorcomprising a cap inclosingsaid circuit terminals and secured inposltlon, a sleeve ofconducting material arranged outside of said capand having an end shouldered and reduced to bear against the end of saidcap and fit into an aperture therein, an insulating washer locatedagainst the end of said sleeve, a secsaid cap and in electricalconnection with the first mentioned sleeve, a screw extending throughsaid tubular bushing and havin electrical contact with the secondmentione sleeve, an insulating washer mounted on said screw next to saidcontact member, and a second spring contact member mounted on said screwagainst said washer, and a nut engaging said screw to unite the parts ofsaid plug to said cap, said contact members being adapted to makeelectrical contact with said circuit terminals.

4. In a device of the character described, a receptacle chambered toreceive a plug, apertures in the wall of said receptacle out ofalinement with one another, ball contacts located in said apertures andnormally projecting into said chamber, yielding means for holding saidcontacts. in normal position, and electrical connections between saidcontacts and a Supply circuit. in combination with a plug fittingthe'chamber, said lug includin contact members insulated om one anot erand circumferentially channeled to electrically and mechanically engagewith said ball contact and permit relative rotation between said plugand receptacle.

I 5. In a device of the character described, a chambered receptacle, aplug to fitsaid chamber, and a single means supported and movable in thewall of said receptacle for detachably uniting said parts bothelectritation between them!v r 6. The combination with exposed circuitterminals, of a cap inclosing said terminals, a plug supported by saidcap and having contact sleeves insulated from one another, contactsmounted onfthe end of said plu within said cap and adapted to engage saicircuit terminals, and an-insulating washer.

separating said contacts and having its edge notched to receive saidcontacts.

ceive said spring contacts, and fastening 10 screws for securing saidcap with its supported plug in position, said screws passing throughnotches formed in the edge of said washer.

FREDERICK E. CARLSON. Witnesses:

JEssE J. FOSTER, M. HA'rroN,

